Embodiments of the invention relate generally to nut retention devices and, more particularly, to nut retention devices having a strap that can be fixedly engaged to a distal end of a threaded member without damage to the threaded member or nut, thereby permitting their reuse.
Nuts and threaded members, such as bolts, are employed to fasten a wide variety of machine components. In many applications, however, operation of the machine causes vibrational or other stresses on the threaded member assembly, which may result in loosening or loss of the nut. In such applications, devices may be employed to retain the nut on the threaded member, preventing its loosening or loss. Such devices typically require inclusion with the threaded member assembly stock or fixed attachment to the nut or threaded member, causing damage to either or both and preventing their reuse after disassembly. For example, many such devices require that the threaded member be cut in order to disassemble the threaded member assembly, requiring replacement of the entire assembly.
This process can become quite expensive in applications where the nut and threaded member assemblies are themselves expensive, such as in gas turbine applications. This expense is exacerbated where periodic or frequent disassembly and reassembly of the nut and threaded member assembly is required, such as, for example, machine maintenance or the replacement of machine parts. Each disassembly requires destruction of the nut and threaded member assembly in place and replacement with a new nut and threaded member assembly, to which a new retention device is then applied.
In addition, some applications simply require a greater degree of retentive strength and/or additional points of retention. For example, nut and threaded member assemblies employed in gas turbine applications, particularly in connection with gas turbine combustion components such as the mounting of combustion transition pieces in a gas turbine, are subjected to high stresses during operation of the gas turbine. This situation requires not only a greater degree of retention, but often the use of very strong, expensive nut and threaded member assemblies. While the use of nut retention devices is often necessary in such situations, the destruction of such expensive nut and threaded member assemblies each time disassembly is required greatly increases the cost of operation of the gas turbine.